Stent Placement to Prevent Restenosis After Angioplasty in Small Coronary Arteries - Stent Placement to Prevent Restenosis After Angioplasty

Description:

Stent Placement to Prevent Restenosis After Angioplasty in Small Coronary Arteries

Hypothesis:

Data on stenting of small coronary arteries have been conflicting. The objective of this study was to compare stenting of small vessels with PTCA.

Study Design

Study Design:

Patients Enrolled: 351

Primary Endpoints:

The primary end point was angiographic restenosis defined as >/= 50% diameter stenosis at 6-month follow-up.

Secondary Endpoints:

Secondary end points included angiographic success (< 50% residual stenosis by QCA), procedure success defined as < 50% diameter stenosis by visual assessment, clinical success defined as angiographic success in the absence of death, myocardial infarction (MI), bypass surgery and target vessel vascularization (TVR) within the same hospitalization, TVR at 6 months, absolute minimal luminal diameter post procedure and at follow-up and Canadian Cardiovascular Society functional class, medication and repeat revascularization at 1 year.

Drug/Procedures Used:

Patients with stable angina, stabilized unstable angina or documented silent ischemia with a de novo lesion and with a reference vessel diameter between 2.3mm and 2.9mm were randomized to stent implantation (169 patients) or PTCA (182 patients). The angiographic target was < 30% residual stenosis. Crossover to stent implantation was allowed for abrupt closure, threatened closure, TIMI flow < 3 or >/= 50% residual stenosis. The coronary stents used were 15mm pre-mounted stents available in 2.5mm and 3mm diameters.

Principal Findings:

In the stent group, four patients (2.4%) crossed over to angioplasty because of inability to cross the lesion with the stent. In the angioplasty group, 37 patients (20.3%) crossed over to stent implantation as a bailout procedure. Angiographic success was achieved in 98.2% of stent patients vs. 93.9% of PTCA patients (p=0.0065). Clinical success was greater in the stent group (95.3% vs. 87.9%, p=0.0066). There were no differences in major in-hospital cardiac complications including death (0% vs. 0%), Q-wave MI (0% vs. 0%), non–Q-wave MI (4.9% in the PTCA group vs. 1.8% in the stent group, p=0.142), coronary artery bypass surgery (0.5% vs. 0.6% ns) and repeat angioplasty (2.7% vs. 0.6%, p=0.21%). There was a trend toward a lower incidence of any event in the stent group compared to the angioplasty group (3.0% vs. 7.1%, p=0.07). Post-procedure residual stenosis was significantly lower after stenting (12.4 +/- 9.0% vs. 25.6 +/- 15.1%, p=0.001). At 6-month follow-up, the restenosis rate was 28.8% in the stent group and 32.8% in the angioplasty group (p=ns), while TVR was required in 17.8% and 20.3% of patients, respectively (p=0.54). There were no differences in major cardiac events including death, MI, non-Q-wave MI and coronary artery bypass surgery.

When compared with PTCA, stenting of small vessels results in similar restenosis rates and acute long-term outcomes.

Interpretation:

The results of this study support prior studies that have shown that in small vessels, a strategy of elective stenting results in similar acute and long-term outcomes when compared to a strategy of PTCA with provisional stenting. The authors conclude that due to a trend toward a lower in-house complication rate, a strategy of elective stenting may be a superior strategy in this patient population. This lower complication rate in the stent group was primarily driven by a lower incidence of non-Q-wave MI.

Keywords: Follow-Up Studies, Angina, Stable, Constriction, Pathologic, Coronary Vessels, Coronary Artery Bypass, Angioplasty, Stents


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